Abstract: Transfer roller(s) is/are such that either end thereof is formed from fibrous electrically conductive component(s) and such that cylindrical portion(s) in central region(s) is/are, for example, formed from metal roller-like structure(s), either fibrous electrically conductive component outer end being arranged so as to extend somewhat beyond either transfer/transport belt side. Furthermore, outside diameter(s) approximated by tips of respective individual fiber(s) of fibrous electrically conductive component(s) is/are somewhat larger than diameter(s) of metal roller-like structure(s). This makes it possible for electric field(s) to be applied, and for charging to occur, along the full width(s) of transfer/transport belt(s).

Abstract: A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations.

Abstract: An embodiment of a screw conveyor includes a rotating shaft and a conveying blade helically formed around and loosely coupled with the rotating shaft. One or both of two edges of the conveying blade is/are only fixed to the rotating shaft, and a gap is provided between the rotating shaft and the conveying blade. Thereby, the conveying blade can be vibrated in a center axis direction of the rotating shaft by rotation of the rotating shaft and conveyed waste developer.

Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Abstract: A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

Abstract: A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

Abstract: An object of the invention is to convey a transfer material properly and securely in a simple structure even where space allowance is limited. An image forming apparatus has a photoconductive body and a transfer device composed of a transfer roller. After a developer image formed on the photoconductive body is electrostatically transferred onto a sheet by the transfer roller, a rear end of the sheet having passed through opposed regions of the transfer roller and the photoconductive body is, by a guiding roller arranged at a downstream side of the opposed portions along a sheet conveying path, guided in conveyance from a non-transferred surface of the transfer material so that it is kept out of contact with the transfer roller.

Abstract: An object of the invention is to convey a transfer material properly and securely in a simple structure even where space allowance is limited. An image forming apparatus has a photoconductive body and a transfer device composed of a transfer roller. After a developer image formed on the photoconductive body is electrostatically transferred onto a sheet by the transfer roller, a rear end of the sheet having passed through opposed regions of the transfer roller and the photoconductive body is, by a guiding roller arranged at a downstream side of the opposed portions along a sheet conveying path, guided in conveyance from a non-transferred surface of the transfer material so that it is kept out of contact with the transfer roller.

Abstract: A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

Abstract: In a paper-punching device for use in an image-forming apparatus, the rear edge of a sheet of paper that is being transported through a transport guide is detected by the photosensor. After a predetermined time has passed since the detection, a punching device is activated. At this time, a punching member is depressed downward, and a punching blade attached to its top penetrates through the sheet of paper, thereby forming a punch hole. Even during the punching operation, transport rollers continue to rotate. Therefore, when the sheet of paper is caught by the punching blade, the transport rollers are allowed to slip predetermined amount with respect to the paper. For this reason, at least one of the transport rollers is made of a foamed material. With this arrangement, since the punching operation is carried out on the rear side of the sheet of paper, it becomes possible to reduce the occurrence of paper jams even if sheets of paper are transported in succession.

Abstract: An inverter-driven motor which is driven by an inverter power source and includes an insulating member for insulating a winding wire and an iron core of the inverter-driven motor from each other at a groove. The insulating member is formed by not less than two insulating films and at least one of the insulating films is formed with a plurality of bores.

Abstract: A toner replenishing device has a hopper for storing toner. The hopper has an L-shaped so as to have a large volume in a lateral direction, thereby ensuring that the hopper has the volume corresponding to several toner containers. The toner stored in a lower portion of the hopper is transported by toner transport devices to the vicinity of a toner supply opening provided on the tip of the hopper. The remaining amount of toner is detected by sensors that detect the amount of toner remaining in the toner replenishing device step-by-step. This results in a toner replenishing device having a large toner storage section (1) in which the aggregation of toner due to dead weight can be prevented and (2) in which the amount of toner remaining can be displayed step-by-step and the supply of toner can be carried out in advance before a shortage of toner occurs.

Abstract: In a paper-punching device for use in an image-forming apparatus, the rear edge of a sheet of paper that is being transported through a transport guide is detected by the photosensor. After a predetermined time has passed since the detection, a punching device is activated. At this time, a punching member is depressed downward, and a punching blade attached to its top penetrates through the sheet of paper, thereby forming a punch hole. Even during the punching operation, transport rollers continue to rotate. Therefore, when the sheet of paper is caught by the punching blade, the transport rollers are allowed to slip a predetermined amount with respect to the paper. For this reason, at least one of the transport rollers is made of a foamed material. With this arrangement, since the punching operation is carried out on the rear side of the sheet of paper, it becomes possible to reduce the occurrence of paper jams even if sheets of paper are transported in succession.

Abstract: An image forming apparatus has a jam sensor for detecting a jammed sheets in a transporting path, a paper guide which can be switched between a close state that guides sheets to an image forming section and an open state that make a jammed sheet removable, a movable backward end plate which is provided on an ADU tray and regulates a position of stored sheets according to the size of sheet, and a pulse motor that moves the movable backward end plate. When the paper guide is converted to the open state, an interference section where the movable backward end plate contacts with the paper guide and a non-interference section are formed. The image forming apparatus is provided with a CPU which drives the pulse motor so as to move the movable backward end plate to the non-interference section based upon a jam detecting signal from the jam sensor.

Abstract: A paper feeder includes a feed roller and a reverse roller urged against the feed roller by a fulcrum. The fulcrum is located at a specific angles as measured from plane parallel to the contact area of the rollers clockwise from the feed direction of one sheet of paper. The specific angles results in a widened range of the contact pressure between the rollers.

Abstract: Waste toner is collected in a collecting container. When a full-state condition of the collecting container is detected; if a door is opened, a stepping motor is activated to move the collecting container from a mounted position to a demounting position. In an operational situation where a paper-guide plate is opened when a paper jam is detected in a vertical conveyer; even if the collecting container is full, the collecting container remains at a stand still at the mounted position. When the full collecting container is replaced with an empty collecting container at the demounting position, the stepping motor is activated to rotate in the reverse direction so that the collecting container is returned from the demounting position to the mounted position. The collecting container when filled can optionally be moved by a mechanical weight system. Optionally the container can be moved to a mounted position manually.